Protein Modifications and Proteomics

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Many times proteins are modified after synthesis. These modifications refer to any alteration in the amino acid sequence of the protein or modification of amino acid side chain or terminal amino or carboxyl group. Generally, these post translational modifications influence the structure, stability, activity, cellular localization or substrate specificity of the protein. Post translational modification provides complexity to proteome for diverse function with limited number of genes (Fig. 1).

Figure 1: Complexity to proteome for diverse function with limited number of genes

Post-translational modifications (PTMs) mainly occur in the endoplasmic reticulum of the cell but sometimes continue in the golgibody as well. Though there are different types of PTMs, but the most predominant among them are:-

⇒  Proteolysis
⇒  Glycosylation
⇒  Ubiquitinylation